If there are adverts in the launcher, would they only be static images (and gifs, like in the first launcher) and text? I don't like the flash adverts, as I found they slowed down my browser (and may also be a security risk).
I've already found the source code on github, is it working at the moment?

That means the chunk has been corrupted, you'll need to ask the owner to regenerate the corrupted chunk. The cause of the corruption was likely due to someone placing a drawbridge inside of the drawbridge camoflauge slot.

go to %appdata%, and navigate to .technic/tekkit/config
Open the IC2ChargingBench.cfg with notepad, and change the block id from 189 to 187.
Navigate back to ./technic/tekkit, and open up the buildcraft folder, followed by the config folder inside.
Open the AdditionalPipes.cfg with notepad, and change the TeleportTether.id = to 179.

You have an ID conflict for some reason. The default ID for the Charging Bench in Tekkit Classic is 187, while the Teleport tether is 179. I would recommend changing the ids in the config files to those values.

There is an option to increase the amount of memory, and automatically increase the perm gen size, but there isn't a way within the launcher to launch minecraft with manually entered java parameters (the JVM Arguments).

Something that I feel that the Technic Launcher is currently missing is the ability to manually enter in Advanced Java Parameters. Other launchers (including the new minecraft launcher, and MultiMC), have this box so parameters can be entered to fix memory problems with Minecraft.